.row
  %h3.set_title 设置
  = render 'set_sidebar'
  .col-md-8
    = form_for :user, url: set_userinfo_blogs_path, role: 'form' do |f|
      .form-group
        %label{for: 'user_nick_name'} 昵称
        = f.text_field :nick_name, value: @current_user.nickname, placeholder: '昵称', class: 'form-control', size: 10
      .form-group
        %label{for: 'user_avatar'} 头像
        .row.text-left
          .col-md-2#img_preview
            %img#set_user_avatar{src: "#{avatar_url(@current_user)}"}
          .col-md-8.avatar-field
            = f.file_field :avatar
      .form-group
        = f.submit '修改', class: 'btn btn-primary set-btn'


:javascript
  function previewImage(file){
    var MAXWIDTH  = 80;
    var MAXHEIGHT = 80;
    var div = document.getElementById('img_preview');
    if (file.files && file.files[0])
    {
      div.innerHTML = '<img id=imghead>';
      var img = document.getElementById('imghead');
      img.onload = function(){
        var rect = clacImgZoomParam(MAXWIDTH, MAXHEIGHT, img.offsetWidth, img.offsetHeight);
        img.height = rect.height;
        img.style.marginTop = rect.top+'px';
      }
      var reader = new FileReader();
      reader.onload = function(evt){img.src = evt.target.result;}
      reader.readAsDataURL(file.files[0]);
    }
    else
    {
      var sFilter='filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src="';
      file.select();
      var src = document.selection.createRange().text;
      div.innerHTML = '<img id=imghead>';
      var img = document.getElementById('imghead');
      img.filters.item('DXImageTransform.Microsoft.AlphaImageLoader').src = src;
      var rect = clacImgZoomParam(MAXWIDTH, MAXHEIGHT, img.offsetWidth, img.offsetHeight);
      status =('rect:'+rect.top+','+rect.left+','+rect.width+','+rect.height);
      div.innerHTML = "<div id=divhead style='width:"+rect.width+"px;height:"+rect.height+"px;margin-top:"+rect.top+"px;margin-left:"+rect.left+"px;"+sFilter+src+"\"'></div>";
    }
  }

  function clacImgZoomParam( maxWidth, maxHeight, width, height ){
    var param = {top:0, left:0, width:width, height:height};
    if( width>maxWidth || height>maxHeight )
    {
      rateWidth = width / maxWidth;
      rateHeight = height / maxHeight;

      if( rateWidth > rateHeight )
      {
        param.width =  maxWidth;
        param.height = Math.round(height / rateWidth);
      }else
      {
        param.width = Math.round(width / rateHeight);
        param.height = maxHeight;
      }
    }

    param.left = Math.round((maxWidth - param.width) / 2);
    param.top = Math.round((maxHeight - param.height) / 2);
    return param;
  }

  $(function(){
    $("#user_avatar").change(function() {
      previewImage(this);
    });
  });